Abstract/Summary

Indoor plants are introduced into buildings to benefit the occupants’ health and well-being, but their room-scale impact and effect on people’s responses is poorly understood. Through experiments in controlled chambers, naturally ventilated offices and measurements of people’s psychological responses, this thesis investigated interactions between the plant, indoor air quality (IAQ) and building occupants. There were significant differences between the plants’ performance in chamber-scale versus room-scale experiments. Species selection, leaf area and planting density were identified as key factors for maximising [CO2] reduction and adding moisture to indoor environments. Most moisture was added by plants in hot, dry environments. At office-scale, the building design, air change rate (ACH) and environmental conditions had a greater impact than the plants on the rate of CO2 and moisture removal from the office (28m3 ). There was a seasonal variation in the ACH and the plants’ evapotranspiration rate, with the highest rates in the summer. In the offices the plants emitted 35-68 g of water vapour/day/plant depending on the species and environmental conditions, but 65% -100% was lost through air exchange and absorption. No significant impact on the [CO2] reduction ratewas determined. Whilst the impact of potted plants on IAQ was small or insignificant at office-scale, the physical appearance of the plant had a significant impact on 520 participants, whose responses were measured through a photo-questionnaire. All healthy plants were perceived to positively impact wellbeing and IAQ. An unhealthy plant was perceived negatively for wellbeing and IAQ impacts. Perceptions of wellbeing benefits were affected by the participants’ perceived interest and beauty of the plant. Perceived IAQ benefits were associated with the healthiness of the plant appearance and canopy density. Participants perceived the plants would have a greater benefit for their well�being than for IAQ